Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds billing context (20 credits, Tier 2) and the group tag, which is useful, but says nothing about output shape, computation time, or failure modes beyond what annotations provide.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Extremely tight: one content line plus standardized Group/Cost metadata, front-loaded with the defining term. No filler or redundancy; the only knock is that the parenthetical domain hint is thin.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values need not be described. For a 15-parameter divisional-chart tool with low schema coverage, the description is barely sufficient—it identifies the chart but gives no practical caller guidance. Adequate but with clear gaps.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is only 33% across 15 parameters, so the description carries a compensation burden it does not meet. It offers zero parameter meaning (ayanamsa, houseSystem, timezone, fields, etc. are undocumented in the description), leaving several inputs without clear semantics.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States the specific artifact (Dwadasamsa / D12 divisional chart) and its interpretive domain (parents, ancestral karma). The 'D12'/'Dwadasamsa' label clearly distinguishes it from the many sibling varga tools (d1, d2, d9, d60, etc.). Lacks an explicit verb, but the resource is unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

No when-to-use, prerequisite, or alternative guidance. The parenthetical hint ('parents, ancestral karma') implies the interpretive context but does not tell the agent when to pick D12 over another divisional chart or the general vedic_divisional sibling.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.